[mirror_edk2.git] / ArmPkg / Filesystem / SemihostFs / Arm / SemihostFs.c

/** @file\r
  Support a Semi Host file system over a debuggers JTAG\r
\r
  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>\r
  Portions copyright (c) 2011 - 2021, Arm Limited. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <Uefi.h>\r
\r
#include <Guid/FileInfo.h>\r
#include <Guid/FileSystemInfo.h>\r
#include <Guid/FileSystemVolumeLabelInfo.h>\r
\r
#include <Library/BaseLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/SemihostLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/UefiLib.h>\r
\r
#include <Protocol/DevicePath.h>\r
#include <Protocol/SimpleFileSystem.h>\r
\r
#include "SemihostFs.h"\r
\r
#define DEFAULT_SEMIHOST_FS_LABEL   L"SemihostFs"\r
\r
STATIC CHAR16 *mSemihostFsLabel;\r
\r
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL gSemihostFs = {\r
  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION,\r
  VolumeOpen\r
};\r
\r
EFI_FILE gSemihostFsFile = {\r
  EFI_FILE_PROTOCOL_REVISION,\r
  FileOpen,\r
  FileClose,\r
  FileDelete,\r
  FileRead,\r
  FileWrite,\r
  FileGetPosition,\r
  FileSetPosition,\r
  FileGetInfo,\r
  FileSetInfo,\r
  FileFlush\r
};\r
\r
//\r
// Device path for semi-hosting. It contains our autogened Caller ID GUID.\r
//\r
typedef struct {\r
  VENDOR_DEVICE_PATH        Guid;\r
  EFI_DEVICE_PATH_PROTOCOL  End;\r
} SEMIHOST_DEVICE_PATH;\r
\r
SEMIHOST_DEVICE_PATH gDevicePath = {\r
  {\r
    { HARDWARE_DEVICE_PATH, HW_VENDOR_DP, { sizeof (VENDOR_DEVICE_PATH), 0 } },\r
    EFI_CALLER_ID_GUID\r
  },\r
  { END_DEVICE_PATH_TYPE, END_ENTIRE_DEVICE_PATH_SUBTYPE, { sizeof (EFI_DEVICE_PATH_PROTOCOL), 0 } }\r
};\r
\r
typedef struct {\r
  LIST_ENTRY    Link;\r
  UINT64        Signature;\r
  EFI_FILE      File;\r
  CHAR8         *FileName;\r
  UINT64        OpenMode;\r
  UINT32        Position;\r
  UINTN         SemihostHandle;\r
  BOOLEAN       IsRoot;\r
  EFI_FILE_INFO Info;\r
} SEMIHOST_FCB;\r
\r
#define SEMIHOST_FCB_SIGNATURE      SIGNATURE_32( 'S', 'H', 'F', 'C' )\r
#define SEMIHOST_FCB_FROM_THIS(a)   CR(a, SEMIHOST_FCB, File, SEMIHOST_FCB_SIGNATURE)\r
#define SEMIHOST_FCB_FROM_LINK(a)   CR(a, SEMIHOST_FCB, Link, SEMIHOST_FCB_SIGNATURE);\r
\r
EFI_HANDLE  gInstallHandle = NULL;\r
LIST_ENTRY  gFileList = INITIALIZE_LIST_HEAD_VARIABLE (gFileList);\r
\r
SEMIHOST_FCB *\r
AllocateFCB (\r
  VOID\r
  )\r
{\r
  SEMIHOST_FCB *Fcb;\r
\r
  Fcb = AllocateZeroPool (sizeof (SEMIHOST_FCB));\r
  if (Fcb != NULL) {\r
    CopyMem (&Fcb->File, &gSemihostFsFile, sizeof (gSemihostFsFile));\r
    Fcb->Signature = SEMIHOST_FCB_SIGNATURE;\r
  }\r
\r
  return Fcb;\r
}\r
\r
VOID\r
FreeFCB (\r
  IN SEMIHOST_FCB *Fcb\r
  )\r
{\r
  // Remove Fcb from gFileList.\r
  RemoveEntryList (&Fcb->Link);\r
\r
  // To help debugging...\r
  Fcb->Signature = 0;\r
\r
  FreePool (Fcb);\r
}\r
\r
\r
\r
EFI_STATUS\r
VolumeOpen (\r
  IN  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *This,\r
  OUT EFI_FILE                        **Root\r
  )\r
{\r
  SEMIHOST_FCB *RootFcb;\r
\r
  if (Root == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  RootFcb = AllocateFCB ();\r
  if (RootFcb == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  RootFcb->IsRoot = TRUE;\r
  RootFcb->Info.Attribute = EFI_FILE_READ_ONLY | EFI_FILE_DIRECTORY;\r
\r
  InsertTailList (&gFileList, &RootFcb->Link);\r
\r
  *Root = &RootFcb->File;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Open a file on the host system by means of the semihosting interface.\r
\r
  @param[in]   This        A pointer to the EFI_FILE_PROTOCOL instance that is\r
                           the file handle to source location.\r
  @param[out]  NewHandle   A pointer to the location to return the opened\r
                           handle for the new file.\r
  @param[in]   FileName    The Null-terminated string of the name of the file\r
                           to be opened.\r
  @param[in]   OpenMode    The mode to open the file : Read or Read/Write or\r
                           Read/Write/Create\r
  @param[in]   Attributes  Only valid for EFI_FILE_MODE_CREATE, in which case these\r
                           are the attribute bits for the newly created file. The\r
                           mnemonics of the attribute bits are : EFI_FILE_READ_ONLY,\r
                           EFI_FILE_HIDDEN, EFI_FILE_SYSTEM, EFI_FILE_RESERVED,\r
                           EFI_FILE_DIRECTORY and EFI_FILE_ARCHIVE.\r
\r
  @retval  EFI_SUCCESS            The file was open.\r
  @retval  EFI_NOT_FOUND          The specified file could not be found.\r
  @retval  EFI_DEVICE_ERROR       The last issued semi-hosting operation failed.\r
  @retval  EFI_WRITE_PROTECTED    Attempt to create a directory. This is not possible\r
                                  with the semi-hosting interface.\r
  @retval  EFI_OUT_OF_RESOURCES   Not enough resources were available to open the file.\r
  @retval  EFI_INVALID_PARAMETER  At least one of the parameters is invalid.\r
\r
**/\r
EFI_STATUS\r
FileOpen (\r
  IN  EFI_FILE  *This,\r
  OUT EFI_FILE  **NewHandle,\r
  IN  CHAR16    *FileName,\r
  IN  UINT64    OpenMode,\r
  IN  UINT64    Attributes\r
  )\r
{\r
  SEMIHOST_FCB   *FileFcb;\r
  RETURN_STATUS  Return;\r
  EFI_STATUS     Status;\r
  UINTN          SemihostHandle;\r
  CHAR8          *AsciiFileName;\r
  UINT32         SemihostMode;\r
  UINTN          Length;\r
\r
  if ((FileName == NULL) || (NewHandle == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if ( (OpenMode != EFI_FILE_MODE_READ) &&\r
       (OpenMode != (EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE)) &&\r
       (OpenMode != (EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE | EFI_FILE_MODE_CREATE)) ) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (((OpenMode & EFI_FILE_MODE_CREATE) != 0) &&\r
      ((Attributes & EFI_FILE_DIRECTORY) != 0)) {\r
    return EFI_WRITE_PROTECTED;\r
  }\r
\r
  Length = StrLen (FileName) + 1;\r
  AsciiFileName = AllocatePool (Length);\r
  if (AsciiFileName == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
  UnicodeStrToAsciiStrS (FileName, AsciiFileName, Length);\r
\r
  // Opening '/', '\', '.', or the NULL pathname is trying to open the root directory\r
  if ((AsciiStrCmp (AsciiFileName, "\\") == 0) ||\r
      (AsciiStrCmp (AsciiFileName, "/")  == 0) ||\r
      (AsciiStrCmp (AsciiFileName, "")   == 0) ||\r
      (AsciiStrCmp (AsciiFileName, ".")  == 0)    ) {\r
    FreePool (AsciiFileName);\r
    return (VolumeOpen (&gSemihostFs, NewHandle));\r
  }\r
\r
  //\r
  // No control is done here concerning the file path. It is passed\r
  // as it is to the host operating system through the semi-hosting\r
  // interface. We first try to open the file in the read or update\r
  // mode even if the file creation has been asked for. That way, if\r
  // the file already exists, it is not truncated to zero length. In\r
  // write mode (bit SEMIHOST_FILE_MODE_WRITE up), if the file already\r
  // exists, it is reset to an empty file.\r
  //\r
  if (OpenMode == EFI_FILE_MODE_READ) {\r
    SemihostMode = SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY;\r
  } else {\r
    SemihostMode = SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY | SEMIHOST_FILE_MODE_UPDATE;\r
  }\r
  Return = SemihostFileOpen (AsciiFileName, SemihostMode, &SemihostHandle);\r
\r
  if (RETURN_ERROR (Return)) {\r
    if ((OpenMode & EFI_FILE_MODE_CREATE) != 0) {\r
      //\r
      // In the create if does not exist case, if the opening in update\r
      // mode failed, create it and open it in update mode. The update\r
      // mode allows for both read and write from and to the file.\r
      //\r
      Return = SemihostFileOpen (\r
                 AsciiFileName,\r
                 SEMIHOST_FILE_MODE_WRITE | SEMIHOST_FILE_MODE_BINARY | SEMIHOST_FILE_MODE_UPDATE,\r
                 &SemihostHandle\r
                 );\r
      if (RETURN_ERROR (Return)) {\r
        Status = EFI_DEVICE_ERROR;\r
        goto Error;\r
      }\r
    } else {\r
      Status = EFI_NOT_FOUND;\r
      goto Error;\r
    }\r
  }\r
\r
  // Allocate a control block and fill it\r
  FileFcb = AllocateFCB ();\r
  if (FileFcb == NULL) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto Error;\r
  }\r
\r
  FileFcb->FileName       = AsciiFileName;\r
  FileFcb->SemihostHandle = SemihostHandle;\r
  FileFcb->Position       = 0;\r
  FileFcb->IsRoot         = 0;\r
  FileFcb->OpenMode       = OpenMode;\r
\r
  Return = SemihostFileLength (SemihostHandle, &Length);\r
  if (RETURN_ERROR (Return)) {\r
    Status = EFI_DEVICE_ERROR;\r
    FreeFCB (FileFcb);\r
    goto Error;\r
  }\r
\r
  FileFcb->Info.FileSize     = Length;\r
  FileFcb->Info.PhysicalSize = Length;\r
  FileFcb->Info.Attribute    = ((OpenMode & EFI_FILE_MODE_CREATE) != 0) ?\r
                                 Attributes : 0;\r
\r
  InsertTailList (&gFileList, &FileFcb->Link);\r
\r
  *NewHandle = &FileFcb->File;\r
\r
  return EFI_SUCCESS;\r
\r
Error:\r
\r
  FreePool (AsciiFileName);\r
\r
  return Status;\r
}\r
\r
/**\r
  Worker function that truncate a file specified by its name to a given size.\r
\r
  @param[in]  FileName  The Null-terminated string of the name of the file to be opened.\r
  @param[in]  Size      The target size for the file.\r
\r
  @retval  EFI_SUCCESS       The file was truncated.\r
  @retval  EFI_DEVICE_ERROR  The last issued semi-hosting operation failed.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
TruncateFile (\r
  IN CHAR8  *FileName,\r
  IN UINTN   Size\r
  )\r
{\r
  EFI_STATUS     Status;\r
  RETURN_STATUS  Return;\r
  UINTN          FileHandle;\r
  UINT8          *Buffer;\r
  UINTN          Remaining;\r
  UINTN          Read;\r
  UINTN          ToRead;\r
\r
  Status     = EFI_DEVICE_ERROR;\r
  FileHandle = 0;\r
  Buffer     = NULL;\r
\r
  Return = SemihostFileOpen (\r
             FileName,\r
             SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY,\r
             &FileHandle\r
             );\r
  if (RETURN_ERROR (Return)) {\r
    goto Error;\r
  }\r
\r
  Buffer = AllocatePool (Size);\r
  if (Buffer == NULL) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto Error;\r
  }\r
\r
  Read = 0;\r
  Remaining = Size;\r
  while (Remaining > 0) {\r
    ToRead = Remaining;\r
    Return = SemihostFileRead (FileHandle, &ToRead, Buffer + Read);\r
    if (RETURN_ERROR (Return)) {\r
      goto Error;\r
    }\r
    Remaining -= ToRead;\r
    Read      += ToRead;\r
  }\r
\r
  Return = SemihostFileClose (FileHandle);\r
  FileHandle = 0;\r
  if (RETURN_ERROR (Return)) {\r
    goto Error;\r
  }\r
\r
  Return = SemihostFileOpen (\r
             FileName,\r
             SEMIHOST_FILE_MODE_WRITE | SEMIHOST_FILE_MODE_BINARY,\r
             &FileHandle\r
             );\r
  if (RETURN_ERROR (Return)) {\r
    goto Error;\r
  }\r
\r
  if (Size > 0) {\r
    Return = SemihostFileWrite (FileHandle, &Size, Buffer);\r
    if (RETURN_ERROR (Return)) {\r
      goto Error;\r
    }\r
  }\r
\r
  Status = EFI_SUCCESS;\r
\r
Error:\r
\r
  if (FileHandle != 0) {\r
    SemihostFileClose (FileHandle);\r
  }\r
  if (Buffer != NULL) {\r
    FreePool (Buffer);\r
  }\r
\r
  return (Status);\r
\r
}\r
\r
/**\r
  Close a specified file handle.\r
\r
  @param[in]  This  A pointer to the EFI_FILE_PROTOCOL instance that is the file\r
                    handle to close.\r
\r
  @retval  EFI_SUCCESS            The file was closed.\r
  @retval  EFI_INVALID_PARAMETER  The parameter "This" is NULL.\r
\r
**/\r
EFI_STATUS\r
FileClose (\r
  IN EFI_FILE  *This\r
  )\r
{\r
  SEMIHOST_FCB   *Fcb;\r
\r
  if (This == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS(This);\r
\r
  if (!Fcb->IsRoot) {\r
    SemihostFileClose (Fcb->SemihostHandle);\r
    //\r
    // The file size might have been reduced from its actual\r
    // size on the host file system with FileSetInfo(). In\r
    // that case, the file has to be truncated.\r
    //\r
    if (Fcb->Info.FileSize < Fcb->Info.PhysicalSize) {\r
      TruncateFile (Fcb->FileName, Fcb->Info.FileSize);\r
    }\r
    FreePool (Fcb->FileName);\r
  }\r
\r
  FreeFCB (Fcb);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Close and delete a file.\r
\r
  @param[in]  This  A pointer to the EFI_FILE_PROTOCOL instance that is the file\r
                    handle to delete.\r
\r
  @retval  EFI_SUCCESS              The file was closed and deleted.\r
  @retval  EFI_WARN_DELETE_FAILURE  The handle was closed, but the file was not deleted.\r
  @retval  EFI_INVALID_PARAMETER    The parameter "This" is NULL.\r
\r
**/\r
EFI_STATUS\r
FileDelete (\r
  IN EFI_FILE *This\r
  )\r
{\r
  SEMIHOST_FCB   *Fcb;\r
  RETURN_STATUS  Return;\r
  CHAR8          *FileName;\r
  UINTN          NameSize;\r
\r
  if (This == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS (This);\r
\r
  if (!Fcb->IsRoot) {\r
    // Get the filename from the Fcb\r
    NameSize = AsciiStrLen (Fcb->FileName);\r
    FileName = AllocatePool (NameSize + 1);\r
\r
    AsciiStrCpyS (FileName, NameSize + 1, Fcb->FileName);\r
\r
    // Close the file if it's open.  Disregard return status,\r
    // since it might give an error if the file isn't open.\r
    This->Close (This);\r
\r
    // Call the semihost interface to delete the file.\r
    Return = SemihostFileRemove (FileName);\r
    if (RETURN_ERROR (Return)) {\r
      return EFI_WARN_DELETE_FAILURE;\r
    }\r
    return EFI_SUCCESS;\r
  } else {\r
    return EFI_WARN_DELETE_FAILURE;\r
  }\r
}\r
\r
/**\r
  Read data from an open file.\r
\r
  @param[in]      This        A pointer to the EFI_FILE_PROTOCOL instance that\r
                              is the file handle to read data from.\r
  @param[in out]  BufferSize  On input, the size of the Buffer. On output, the\r
                              amount of data returned in Buffer. In both cases,\r
                              the size is measured in bytes.\r
  @param[out]     Buffer      The buffer into which the data is read.\r
\r
  @retval  EFI_SUCCESS            The data was read.\r
  @retval  EFI_DEVICE_ERROR       On entry, the current file position is\r
                                  beyond the end of the file, or the semi-hosting\r
                                  interface reported an error while performing the\r
                                  read operation.\r
  @retval  EFI_INVALID_PARAMETER  At least one of the three input pointers is NULL.\r
\r
**/\r
EFI_STATUS\r
FileRead (\r
  IN     EFI_FILE  *This,\r
  IN OUT UINTN     *BufferSize,\r
  OUT    VOID      *Buffer\r
  )\r
{\r
  SEMIHOST_FCB   *Fcb;\r
  EFI_STATUS     Status;\r
  RETURN_STATUS  Return;\r
\r
  if ((This == NULL) || (BufferSize == NULL) || (Buffer == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS (This);\r
\r
  if (Fcb->IsRoot) {\r
    // The semi-hosting interface does not allow to list files on the host machine.\r
    Status = EFI_UNSUPPORTED;\r
  } else {\r
    Status = EFI_SUCCESS;\r
    if (Fcb->Position >= Fcb->Info.FileSize) {\r
      *BufferSize = 0;\r
      if (Fcb->Position > Fcb->Info.FileSize) {\r
        Status = EFI_DEVICE_ERROR;\r
      }\r
    } else {\r
      Return = SemihostFileRead (Fcb->SemihostHandle, BufferSize, Buffer);\r
      if (RETURN_ERROR (Return)) {\r
        Status = EFI_DEVICE_ERROR;\r
      } else {\r
        Fcb->Position += *BufferSize;\r
      }\r
    }\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Worker function that extends the size of an open file.\r
\r
  The extension is filled with zeros.\r
\r
  @param[in]  Fcb   Internal description of the opened file\r
  @param[in]  Size  The number of bytes, the file has to be extended.\r
\r
  @retval  EFI_SUCCESS       The file was extended.\r
  @retval  EFI_DEVICE_ERROR  The last issued semi-hosting operation failed.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
ExtendFile (\r
  IN  SEMIHOST_FCB  *Fcb,\r
  IN  UINTN         Size\r
  )\r
{\r
  RETURN_STATUS  Return;\r
  UINTN          Remaining;\r
  CHAR8          WriteBuffer[128];\r
  UINTN          WriteNb;\r
  UINTN          WriteSize;\r
\r
  Return = SemihostFileSeek (Fcb->SemihostHandle, Fcb->Info.FileSize);\r
  if (RETURN_ERROR (Return)) {\r
    return EFI_DEVICE_ERROR;\r
  }\r
\r
  Remaining = Size;\r
  SetMem (WriteBuffer, 0, sizeof(WriteBuffer));\r
  while (Remaining > 0) {\r
    WriteNb = MIN (Remaining, sizeof(WriteBuffer));\r
    WriteSize = WriteNb;\r
    Return = SemihostFileWrite (Fcb->SemihostHandle, &WriteSize, WriteBuffer);\r
    if (RETURN_ERROR (Return)) {\r
      return EFI_DEVICE_ERROR;\r
    }\r
    Remaining -= WriteNb;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Write data to an open file.\r
\r
  @param[in]      This        A pointer to the EFI_FILE_PROTOCOL instance that\r
                              is the file handle to write data to.\r
  @param[in out]  BufferSize  On input, the size of the Buffer. On output, the\r
                              size of the data actually written. In both cases,\r
                              the size is measured in bytes.\r
  @param[in]      Buffer      The buffer of data to write.\r
\r
  @retval  EFI_SUCCESS            The data was written.\r
  @retval  EFI_ACCESS_DENIED      Attempt to write into a read only file or\r
                                  in a file opened in read only mode.\r
  @retval  EFI_DEVICE_ERROR       The last issued semi-hosting operation failed.\r
  @retval  EFI_INVALID_PARAMETER  At least one of the three input pointers is NULL.\r
\r
**/\r
EFI_STATUS\r
FileWrite (\r
  IN     EFI_FILE *This,\r
  IN OUT UINTN    *BufferSize,\r
  IN     VOID     *Buffer\r
  )\r
{\r
  SEMIHOST_FCB   *Fcb;\r
  EFI_STATUS     Status;\r
  UINTN          WriteSize;\r
  RETURN_STATUS  Return;\r
  UINTN          Length;\r
\r
  if ((This == NULL) || (BufferSize == NULL) || (Buffer == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS (This);\r
\r
  // We cannot write a read-only file\r
  if ((Fcb->Info.Attribute & EFI_FILE_READ_ONLY)\r
      || !(Fcb->OpenMode & EFI_FILE_MODE_WRITE)) {\r
    return EFI_ACCESS_DENIED;\r
  }\r
\r
  //\r
  // If the position has been set past the end of the file, first grow the\r
  // file from its current size "Fcb->Info.FileSize" to "Fcb->Position"\r
  // size, filling the gap with zeros.\r
  //\r
  if (Fcb->Position > Fcb->Info.FileSize) {\r
    Status = ExtendFile (Fcb, Fcb->Position - Fcb->Info.FileSize);\r
    if (EFI_ERROR (Status)) {\r
      return Status;\r
    }\r
    Fcb->Info.FileSize = Fcb->Position;\r
  }\r
\r
  WriteSize = *BufferSize;\r
  Return = SemihostFileWrite (Fcb->SemihostHandle, &WriteSize, Buffer);\r
  if (RETURN_ERROR (Return)) {\r
    return EFI_DEVICE_ERROR;\r
  }\r
\r
  Fcb->Position += *BufferSize;\r
  if (Fcb->Position > Fcb->Info.FileSize) {\r
    Fcb->Info.FileSize = Fcb->Position;\r
  }\r
\r
  Return = SemihostFileLength (Fcb->SemihostHandle, &Length);\r
  if (RETURN_ERROR (Return)) {\r
    return EFI_DEVICE_ERROR;\r
  }\r
  Fcb->Info.PhysicalSize = Length;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Return a file's current position.\r
\r
  @param[in]   This      A pointer to the EFI_FILE_PROTOCOL instance that is\r
                         the file handle to get the current position on.\r
  @param[out]  Position  The address to return the file's current position value.\r
\r
  @retval  EFI_SUCCESS            The position was returned.\r
  @retval  EFI_INVALID_PARAMETER  The parameter "This" or "Position" is NULL.\r
\r
**/\r
EFI_STATUS\r
FileGetPosition (\r
  IN  EFI_FILE    *This,\r
  OUT UINT64      *Position\r
  )\r
{\r
  SEMIHOST_FCB *Fcb;\r
\r
  if ((This == NULL) || (Position == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS(This);\r
\r
  *Position = Fcb->Position;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Set a file's current position.\r
\r
  @param[in]  This      A pointer to the EFI_FILE_PROTOCOL instance that is\r
                        the file handle to set the requested position on.\r
  @param[in]  Position  The byte position from the start of the file to set.\r
\r
  @retval  EFI_SUCCESS       The position was set.\r
  @retval  EFI_DEVICE_ERROR  The semi-hosting positioning operation failed.\r
  @retval  EFI_UNSUPPORTED   The seek request for nonzero is not valid on open\r
                             directories.\r
  @retval  EFI_INVALID_PARAMETER  The parameter "This" is NULL.\r
\r
**/\r
EFI_STATUS\r
FileSetPosition (\r
  IN EFI_FILE *This,\r
  IN UINT64   Position\r
  )\r
{\r
  SEMIHOST_FCB   *Fcb;\r
  RETURN_STATUS  Return;\r
\r
  if (This == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS (This);\r
\r
  if (Fcb->IsRoot) {\r
    if (Position != 0) {\r
      return EFI_UNSUPPORTED;\r
    }\r
  }\r
  else {\r
    //\r
    // UEFI Spec section 12.5:\r
    // "Seeking to position 0xFFFFFFFFFFFFFFFF causes the current position to\r
    // be set to the end of the file."\r
    //\r
    if (Position == 0xFFFFFFFFFFFFFFFF) {\r
      Position = Fcb->Info.FileSize;\r
    }\r
    Return = SemihostFileSeek (Fcb->SemihostHandle, MIN (Position, Fcb->Info.FileSize));\r
    if (RETURN_ERROR (Return)) {\r
      return EFI_DEVICE_ERROR;\r
    }\r
  }\r
\r
  Fcb->Position = Position;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Return information about a file.\r
\r
  @param[in]      Fcb         A pointer to the description of an open file.\r
  @param[in out]  BufferSize  The size, in bytes, of Buffer.\r
  @param[out]     Buffer      A pointer to the data buffer to return. Not NULL if\r
                              "*BufferSize" is greater than 0.\r
\r
  @retval  EFI_SUCCESS            The information was returned.\r
  @retval  EFI_BUFFER_TOO_SMALL   The BufferSize is too small to return the information.\r
                                  BufferSize has been updated with the size needed to\r
                                  complete the request.\r
**/\r
STATIC\r
EFI_STATUS\r
GetFileInfo (\r
  IN     SEMIHOST_FCB  *Fcb,\r
  IN OUT UINTN         *BufferSize,\r
  OUT    VOID          *Buffer\r
  )\r
{\r
  EFI_FILE_INFO   *Info;\r
  UINTN           NameSize;\r
  UINTN           ResultSize;\r
  UINTN           Index;\r
\r
  if (Fcb->IsRoot) {\r
    NameSize = 0;\r
    ResultSize = SIZE_OF_EFI_FILE_INFO + sizeof(CHAR16);\r
  } else {\r
    NameSize   = AsciiStrLen (Fcb->FileName) + 1;\r
    ResultSize = SIZE_OF_EFI_FILE_INFO + NameSize * sizeof (CHAR16);\r
  }\r
\r
  if (*BufferSize < ResultSize) {\r
    *BufferSize = ResultSize;\r
    return EFI_BUFFER_TOO_SMALL;\r
  }\r
\r
  Info = Buffer;\r
\r
  // Copy the current file info\r
  CopyMem (Info, &Fcb->Info, SIZE_OF_EFI_FILE_INFO);\r
\r
  // Fill in the structure\r
  Info->Size = ResultSize;\r
\r
  if (Fcb->IsRoot) {\r
    Info->FileName[0]  = L'\0';\r
  } else {\r
    for (Index = 0; Index < NameSize; Index++) {\r
      Info->FileName[Index] = Fcb->FileName[Index];\r
    }\r
  }\r
\r
  *BufferSize = ResultSize;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Return information about a file system.\r
\r
  @param[in]      Fcb         A pointer to the description of an open file\r
                              which belongs to the file system, the information\r
                              is requested for.\r
  @param[in out]  BufferSize  The size, in bytes, of Buffer.\r
  @param[out]     Buffer      A pointer to the data buffer to return. Not NULL if\r
                              "*BufferSize" is greater than 0.\r
\r
  @retval  EFI_SUCCESS            The information was returned.\r
  @retval  EFI_BUFFER_TOO_SMALL   The BufferSize is too small to return the information.\r
                                  BufferSize has been updated with the size needed to\r
                                  complete the request.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
GetFilesystemInfo (\r
  IN     SEMIHOST_FCB *Fcb,\r
  IN OUT UINTN        *BufferSize,\r
  OUT    VOID         *Buffer\r
  )\r
{\r
  EFI_FILE_SYSTEM_INFO  *Info;\r
  EFI_STATUS            Status;\r
  UINTN                 ResultSize;\r
  UINTN                 StringSize;\r
\r
  StringSize = StrSize (mSemihostFsLabel);\r
  ResultSize = SIZE_OF_EFI_FILE_SYSTEM_INFO + StringSize;\r
\r
  if (*BufferSize >= ResultSize) {\r
    ZeroMem (Buffer, ResultSize);\r
    Status = EFI_SUCCESS;\r
\r
    Info = Buffer;\r
\r
    Info->Size       = ResultSize;\r
    Info->ReadOnly   = FALSE;\r
    Info->VolumeSize = 0;\r
    Info->FreeSpace  = 0;\r
    Info->BlockSize  = 0;\r
\r
    CopyMem (Info->VolumeLabel, mSemihostFsLabel, StringSize);\r
  } else {\r
    Status = EFI_BUFFER_TOO_SMALL;\r
  }\r
\r
  *BufferSize = ResultSize;\r
  return Status;\r
}\r
\r
/**\r
  Return information about a file or a file system.\r
\r
  @param[in]      This             A pointer to the EFI_FILE_PROTOCOL instance that\r
                                   is the file handle the requested information is for.\r
  @param[in]      InformationType  The type identifier for the information being requested :\r
                                   EFI_FILE_INFO_ID or EFI_FILE_SYSTEM_INFO_ID or\r
                                   EFI_FILE_SYSTEM_VOLUME_LABEL_ID\r
  @param[in out]  BufferSize       The size, in bytes, of Buffer.\r
  @param[out]     Buffer           A pointer to the data buffer to return. The type of the\r
                                   data inside the buffer is indicated by InformationType.\r
\r
  @retval  EFI_SUCCESS           The information was returned.\r
  @retval  EFI_UNSUPPORTED       The InformationType is not known.\r
  @retval  EFI_BUFFER_TOO_SMALL  The BufferSize is too small to return the information.\r
                                 BufferSize has been updated with the size needed to\r
                                 complete the request.\r
  @retval  EFI_INVALID_PARAMETER  The parameter "This" or "InformationType" or "BufferSize"\r
                                  is NULL or "Buffer" is NULL and "*Buffersize" is greater\r
                                  than 0.\r
\r
**/\r
EFI_STATUS\r
FileGetInfo (\r
  IN     EFI_FILE  *This,\r
  IN     EFI_GUID  *InformationType,\r
  IN OUT UINTN     *BufferSize,\r
  OUT    VOID      *Buffer\r
  )\r
{\r
  SEMIHOST_FCB *Fcb;\r
  EFI_STATUS   Status;\r
  UINTN        ResultSize;\r
\r
  if ((This == NULL)                         ||\r
      (InformationType == NULL)              ||\r
      (BufferSize == NULL)                   ||\r
      ((Buffer == NULL) && (*BufferSize > 0))  ) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS(This);\r
\r
  if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {\r
    Status = GetFilesystemInfo (Fcb, BufferSize, Buffer);\r
  } else if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {\r
    Status = GetFileInfo (Fcb, BufferSize, Buffer);\r
  } else if (CompareGuid (InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {\r
    ResultSize = StrSize (mSemihostFsLabel);\r
\r
    if (*BufferSize >= ResultSize) {\r
      CopyMem (Buffer, mSemihostFsLabel, ResultSize);\r
      Status = EFI_SUCCESS;\r
    } else {\r
      Status = EFI_BUFFER_TOO_SMALL;\r
    }\r
\r
    *BufferSize = ResultSize;\r
  } else {\r
    Status = EFI_UNSUPPORTED;\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Set information about a file.\r
\r
  @param[in]  Fcb   A pointer to the description of the open file.\r
  @param[in]  Info  A pointer to the file information to write.\r
\r
  @retval  EFI_SUCCESS           The information was set.\r
  @retval  EFI_ACCESS_DENIED     An attempt is made to change the name of a file\r
                                 to a file that is already present.\r
  @retval  EFI_ACCESS_DENIED     An attempt is being made to change the\r
                                 EFI_FILE_DIRECTORY Attribute.\r
  @retval  EFI_ACCESS_DENIED     The file is a read-only file or has been\r
                                 opened in read-only mode and an attempt is\r
                                 being made to modify a field other than\r
                                 Attribute.\r
  @retval  EFI_WRITE_PROTECTED   An attempt is being made to modify a\r
                                 read-only attribute.\r
  @retval  EFI_DEVICE_ERROR      The last issued semi-hosting operation failed.\r
  @retval  EFI_OUT_OF_RESOURCES  A allocation needed to process the request failed.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
SetFileInfo (\r
  IN  SEMIHOST_FCB   *Fcb,\r
  IN  EFI_FILE_INFO  *Info\r
  )\r
{\r
  EFI_STATUS     Status;\r
  RETURN_STATUS  Return;\r
  BOOLEAN        FileSizeIsDifferent;\r
  BOOLEAN        FileNameIsDifferent;\r
  BOOLEAN        ReadOnlyIsDifferent;\r
  CHAR8          *AsciiFileName;\r
  UINTN          FileSize;\r
  UINTN          Length;\r
  UINTN          SemihostHandle;\r
\r
  //\r
  // A directory can not be changed to a file and a file can\r
  // not be changed to a directory.\r
  //\r
  if (((Info->Attribute & EFI_FILE_DIRECTORY) != 0) != Fcb->IsRoot) {\r
    return EFI_ACCESS_DENIED;\r
  }\r
\r
  Length = StrLen (Info->FileName) + 1;\r
  AsciiFileName = AllocatePool (Length);\r
  if (AsciiFileName == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
  UnicodeStrToAsciiStrS (Info->FileName, AsciiFileName, Length);\r
\r
  FileSizeIsDifferent = (Info->FileSize != Fcb->Info.FileSize);\r
  FileNameIsDifferent = (AsciiStrCmp (AsciiFileName, Fcb->FileName) != 0);\r
  ReadOnlyIsDifferent = CompareMem (\r
                          &Info->CreateTime,\r
                          &Fcb->Info.CreateTime,\r
                          3 * sizeof (EFI_TIME)\r
                          ) != 0;\r
\r
  //\r
  // For a read-only file or a file opened in read-only mode, only\r
  // the Attribute field can be modified. As the root directory is\r
  // read-only (i.e. VolumeOpen()), this protects the root directory\r
  // description.\r
  //\r
  if ((Fcb->OpenMode == EFI_FILE_MODE_READ)     ||\r
      (Fcb->Info.Attribute & EFI_FILE_READ_ONLY)  ) {\r
    if (FileSizeIsDifferent || FileNameIsDifferent || ReadOnlyIsDifferent) {\r
      Status = EFI_ACCESS_DENIED;\r
      goto Error;\r
    }\r
  }\r
\r
  if (ReadOnlyIsDifferent) {\r
    Status = EFI_WRITE_PROTECTED;\r
    goto Error;\r
  }\r
\r
  Status = EFI_DEVICE_ERROR;\r
\r
  if (FileSizeIsDifferent) {\r
    FileSize = Info->FileSize;\r
    if (Fcb->Info.FileSize < FileSize) {\r
      Status = ExtendFile (Fcb, FileSize - Fcb->Info.FileSize);\r
      if (EFI_ERROR (Status)) {\r
        goto Error;\r
      }\r
      //\r
      // The read/write position from the host file system point of view\r
      // is at the end of the file. If the position from this module\r
      // point of view is smaller than the new file size, then\r
      // ask the host file system to move to that position.\r
      //\r
      if (Fcb->Position < FileSize) {\r
        FileSetPosition (&Fcb->File, Fcb->Position);\r
      }\r
    }\r
    Fcb->Info.FileSize = FileSize;\r
\r
    Return = SemihostFileLength (Fcb->SemihostHandle, &Length);\r
    if (RETURN_ERROR (Return)) {\r
      goto Error;\r
    }\r
    Fcb->Info.PhysicalSize = Length;\r
  }\r
\r
  //\r
  // Note down in RAM the Attribute field but we can not ask\r
  // for its modification to the host file system as the\r
  // semi-host interface does not provide this feature.\r
  //\r
  Fcb->Info.Attribute = Info->Attribute;\r
\r
  if (FileNameIsDifferent) {\r
    Return = SemihostFileOpen (\r
               AsciiFileName,\r
               SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY,\r
               &SemihostHandle\r
               );\r
    if (!RETURN_ERROR (Return)) {\r
      SemihostFileClose (SemihostHandle);\r
      Status = EFI_ACCESS_DENIED;\r
      goto Error;\r
    }\r
\r
    Return = SemihostFileRename (Fcb->FileName, AsciiFileName);\r
    if (RETURN_ERROR (Return)) {\r
      goto Error;\r
    }\r
    FreePool (Fcb->FileName);\r
    Fcb->FileName = AsciiFileName;\r
    AsciiFileName = NULL;\r
  }\r
\r
  Status = EFI_SUCCESS;\r
\r
Error:\r
  if (AsciiFileName != NULL) {\r
    FreePool (AsciiFileName);\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Set information about a file or a file system.\r
\r
  @param[in]  This             A pointer to the EFI_FILE_PROTOCOL instance that\r
                               is the file handle the information is for.\r
  @param[in]  InformationType  The type identifier for the information being set :\r
                               EFI_FILE_INFO_ID or EFI_FILE_SYSTEM_INFO_ID or\r
                               EFI_FILE_SYSTEM_VOLUME_LABEL_ID\r
  @param[in]  BufferSize       The size, in bytes, of Buffer.\r
  @param[in]  Buffer           A pointer to the data buffer to write. The type of the\r
                               data inside the buffer is indicated by InformationType.\r
\r
  @retval  EFI_SUCCESS            The information was set.\r
  @retval  EFI_UNSUPPORTED        The InformationType is not known.\r
  @retval  EFI_DEVICE_ERROR       The last issued semi-hosting operation failed.\r
  @retval  EFI_ACCESS_DENIED      An attempt is being made to change the\r
                                  EFI_FILE_DIRECTORY Attribute.\r
  @retval  EFI_ACCESS_DENIED      InformationType is EFI_FILE_INFO_ID and\r
                                  the file is a read-only file or has been\r
                                  opened in read-only mode and an attempt is\r
                                  being made to modify a field other than\r
                                  Attribute.\r
  @retval  EFI_ACCESS_DENIED      An attempt is made to change the name of a file\r
                                  to a file that is already present.\r
  @retval  EFI_WRITE_PROTECTED    An attempt is being made to modify a\r
                                  read-only attribute.\r
  @retval  EFI_BAD_BUFFER_SIZE    The size of the buffer is lower than that indicated by\r
                                  the data inside the buffer.\r
  @retval  EFI_OUT_OF_RESOURCES   An allocation needed to process the request failed.\r
  @retval  EFI_INVALID_PARAMETER  At least one of the parameters is invalid.\r
\r
**/\r
EFI_STATUS\r
FileSetInfo (\r
  IN EFI_FILE  *This,\r
  IN EFI_GUID  *InformationType,\r
  IN UINTN     BufferSize,\r
  IN VOID      *Buffer\r
  )\r
{\r
  SEMIHOST_FCB          *Fcb;\r
  EFI_FILE_INFO         *Info;\r
  EFI_FILE_SYSTEM_INFO  *SystemInfo;\r
  CHAR16                *VolumeLabel;\r
\r
  if ((This == NULL) || (InformationType == NULL) || (Buffer == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS (This);\r
\r
  if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {\r
    Info = Buffer;\r
    if (Info->Size < (SIZE_OF_EFI_FILE_INFO + StrSize (Info->FileName))) {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
    if (BufferSize < Info->Size) {\r
      return EFI_BAD_BUFFER_SIZE;\r
    }\r
    return SetFileInfo (Fcb, Info);\r
  } else if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {\r
    SystemInfo = Buffer;\r
    if (SystemInfo->Size <\r
        (SIZE_OF_EFI_FILE_SYSTEM_INFO + StrSize (SystemInfo->VolumeLabel))) {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
    if (BufferSize < SystemInfo->Size) {\r
      return EFI_BAD_BUFFER_SIZE;\r
    }\r
    Buffer = SystemInfo->VolumeLabel;\r
\r
    if (StrSize (Buffer) > 0) {\r
      VolumeLabel = AllocateCopyPool (StrSize (Buffer), Buffer);\r
      if (VolumeLabel != NULL) {\r
        FreePool (mSemihostFsLabel);\r
        mSemihostFsLabel = VolumeLabel;\r
        return EFI_SUCCESS;\r
      } else {\r
        return EFI_OUT_OF_RESOURCES;\r
      }\r
    } else {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
  } else if (!CompareGuid (InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {\r
    return EFI_UNSUPPORTED;\r
  } else {\r
    return EFI_UNSUPPORTED;\r
  }\r
}\r
\r
EFI_STATUS\r
FileFlush (\r
  IN EFI_FILE *File\r
  )\r
{\r
  SEMIHOST_FCB *Fcb;\r
\r
  Fcb = SEMIHOST_FCB_FROM_THIS(File);\r
\r
  if (Fcb->IsRoot) {\r
    return EFI_SUCCESS;\r
  } else {\r
    if ((Fcb->Info.Attribute & EFI_FILE_READ_ONLY)\r
        || !(Fcb->OpenMode & EFI_FILE_MODE_WRITE)) {\r
      return EFI_ACCESS_DENIED;\r
    } else {\r
      return EFI_SUCCESS;\r
    }\r
  }\r
}\r
\r
EFI_STATUS\r
SemihostFsEntryPoint (\r
  IN EFI_HANDLE           ImageHandle,\r
  IN EFI_SYSTEM_TABLE     *SystemTable\r
  )\r
{\r
  EFI_STATUS    Status;\r
\r
  Status = EFI_NOT_FOUND;\r
\r
  if (SemihostConnectionSupported ()) {\r
    mSemihostFsLabel = AllocateCopyPool (StrSize (DEFAULT_SEMIHOST_FS_LABEL), DEFAULT_SEMIHOST_FS_LABEL);\r
    if (mSemihostFsLabel == NULL) {\r
      return EFI_OUT_OF_RESOURCES;\r
    }\r
\r
    Status = gBS->InstallMultipleProtocolInterfaces (\r
                    &gInstallHandle,\r
                    &gEfiSimpleFileSystemProtocolGuid, &gSemihostFs,\r
                    &gEfiDevicePathProtocolGuid,       &gDevicePath,\r
                    NULL\r
                    );\r
\r
    if (EFI_ERROR(Status)) {\r
      FreePool (mSemihostFsLabel);\r
    }\r
  }\r
\r
  return Status;\r
}\r